Biomedical subjects

Mingjun Zhang

Publications and source records attributed to Mingjun Zhang.

12 recordsLinked to original sources

PubMed2026

Non-structural maintenance of chromosome condensin I complex subunit H knockdown suppresses malignant progression of esophageal squamous cell carcinoma via the Wnt/β-catenin signaling pathway.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) remains a major cause of cancer-related mortality, and effective therapeutic targets are still limited. Non-structural maintenance of chromosome condensin I complex subunit H (NCAPH) has been implicated in tumorigenesis; however, its clinical relevance, functional roles, and underlying mechanisms in ESCC are not fully defined. We aimed to characterize the expression pattern, prognostic value, biological functions, and mechanistic basis of NCAPH in ESCC. METHODS: Public datasets from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) were analyzed to evaluate NCAPH expression and clinical associations. Single-cell RNA sequencing (scRNA-seq) data were used to map cell-type-specific distribution of NCAPH in tumor and adjacent tissues. NCAPH was silenced in KYSE150 and KYSE510 cells using lentiviral short hairpin RNAs (shRNAs), followed by Cell Counting Kit-8 (CCK-8), colony formation, wound-healing, and Transwell migration/invasion assays. A nude mouse xenograft model was established to assess the effect of NCAPH knockdown in vivo. RNA sequencing (RNA-seq), quantitative polymerase chain reaction (qPCR), western blotting, and enzyme-linked immunosorbent assay (ELISA) were performed to explore potential mechanisms. RESULTS: NCAPH was consistently upregulated in ESCC across multiple cohorts and was associated with unfavorable clinicopathological features and poorer survival. Functional assays demonstrated that NCAPH knockdown significantly inhibited ESCC cell proliferation, migration, invasion, and clonogenic growth. In vivo, NCAPH silencing suppressed xenograft tumor growth. Mechanistically, transcriptomic profiling and molecular validation indicated attenuation of Wnt/β-catenin signaling following NCAPH depletion, accompanied by reduced β-catenin and downstream targets. CONCLUSIONS: NCAPH promotes malignant progression of ESCC, at least in part through activation of the Wnt/β-catenin pathway, and may serve as a potential biomarker and therapeutic target.

Esophageal squamous cell carcinoma (ESCC)↗

PubMed2025

The chromosome-level genome assembly of Prunus cerasifera 'Atropurpurea'.

Prunus cerasifera 'Atropurpurea' (Purpleleaf Plum), known for its unique purple-red foliage, is an important ornamental plant that enhances the aesthetic value of urban greening. To explore the molecular mechanisms underlying leaf color changes, this study assembled the Purpleleaf Plum genome, providing new insights for related research. We used HiFi sequencing data to assemble its genome. After chromosome anchoring, the final genome size was 244.89 Mb, with a contig N50 of 26.60 Mb, and approximately 97.10% of sequences were anchored to 8 chromosomes. Genome annotation identified 28,231 protein-coding genes, with LTR transposons comprising 27.93% of the genome. BUSCO assessment revealed a genome completeness of 98.9%. Telomeric repeat analysis identified 14 telomeres, with six chromosomes capped by double telomeres and two chromosomes containing a single telomere. This high-quality Purpleleaf Plum genome provides a solid foundation for future gene function analysis, cultivar improvement, and genetic research, offering valuable resources for related fields.

Genome, Plant↗

PubMed2006

A computational method to geometric measure of biological particles and application to DNA microarray spot size estimation.

Geometric measures (volume, area and length) of biological particles are of fundamental interest for biological studies. Many times, the measures are at micro-/nano-scale, and based on images of the biological particles. This paper proposes a computational method to geometric measure of biological particles. The method has been applied to DNA microarray spot size estimation. Compared with existing algorithms for microarray spot size estimation, the proposed method is computational efficient and also provides confidence probability on the measure. The contributions of this paper include a generic computational method to geometric measure of biological particles and application to DNA microarray spot size estimation.

Gene Expression Profiling↗

PubMed2006

Inhibition of connective tissue growth factor by siRNA prevents liver fibrosis in rats.

BACKGROUND: Connective tissue growth factor (CTGF) is a highly profibrogenic molecule implicated in hepatic fibrogenesis. Small interfering RNA (siRNA) is an effective tool to silence gene expression post-transcriptionally. Therefore, we conducted an investigation to determine if intraportal vein siRNA injection targeting CTGF inhibits CTGF expression on rat liver in vivo and furthermore whether it protects the liver from liver fibrosis. METHODS: Some rats received carbon tetrachloride (CCl4) by subcutaneous injections every three days for six consecutive weeks, and meantime they also obtained either siRNA (0.1 mg/kg) targeting CTGF, saline or a control siRNA by intraportal vein injection to rats' liver at the same pattern. Other rats received CCl4 by subcutaneous injection for 2 weeks, followed by CCl4 and CTGF siRNA intraportal vein injection for four more weeks. RESULTS: Intraportal vein injection of CTGF siRNA specifically reduced the expression of CTGF protein in rat liver, and these effects were maintained for 3 days. Six weeks after CCl4 injection, prominent upregulations were observed in the gene expressions of CTGF, type I, III collagen, laminin, tissue inhibitor metal proteinase-1 (TIMP-1) and transforming growth factor-beta1 (TGF-beta1) in saline or control siRNA-treated rats livers. Administrating CTGF siRNA for 4 or 6 weeks, by contrast, markedly attenuated the induction of CTGF, type I, III collagen, laminin, TIMP-1 and TGF-beta1 genes, whereas Smad2, 7 gene expression was not affected. The number of active hepatic stellate cells (HSCs) determined by the expression of alpha-smooth muscle actin was also significantly decreased. The CTGF siRNA treatment markedly reduced serum procollagen type III, hepatic hydroxyproline and liver fibrosis staging. CONCLUSIONS: Silencing CTGF expression with siRNA demonstrates therapeutic potential to prevent liver fibrosis by inhibiting HSC activation with consequent extracellular matrix accumulation and the upregulation of TGF-beta1 gene expression.

Animals↗

PubMed2006

A mathematical formulation of DNA computation.

DNA computation is to use DNA molecules for information storing and processing. The task is accomplished by encoding and interpreting DNA molecules in suspended solutions before and after the complementary binding reactions. DNA computation is attractive, due to its fast parallel information processing, remarkable energy efficiency, and high storing capacity. Challenges currently faced by DNA computation are: 1) lack of theoretical computational models for applications and 2) high error rate for implementation. This paper attempts to address these problems from mathematical modeling and genetic coding aspects. The first part of this paper presents a mathematical formulation of DNA computation. The model may serve as a theoretical framework for DNA computation. In the second part, a genetic code based DNA computation approach is presented to reduce error rate for implementation, which has been a major concern for DNA computation. The method provides a promising alternative to reduce error rate for DNA computation.

Base Sequence↗

PubMed2005

Embryonic mouse STO cell-derived xenografts express hepatocytic functions in the livers of nonimmunosuppressed adult rats.

Cells derived from embryonic mouse STO cell lines differentiate into hepatocytes when transplanted into the livers of nonimmunosuppressed dipeptidylpeptidase IV (DPPIV)-negative F344 rats. Within 1 day after intrasplenic injection, donor cells moved rapidly into the liver and were found in intravascular and perivascular sites; by 1 month, they were intrasinusoidal and also integrated into hepatic plates with approximately 2% efficiency and formed conjoint bile canaliculi. Neither donor cell proliferation nor host inflammatory responses were observed during this time. Detection of intrahepatic mouse COX1 mitochondrial DNA and mouse albumin mRNA in recipient rats indicated survival and differentiation of donor cells for at least 3 months. Mouse COX1 targets were also detected intrahepatically 4-9 weeks after STO cell injection into nonimmunosuppressed wild-type rats. In contrast to STO-transplanted rats, mouse DNA or RNA was not detectable in untreated or mock-transplanted rats or in rats injected with donor cell DNA. In cultured STO donor cells, DPPIV and glucose-6-phosphatase activities were observed in small clusters; in contrast, mouse major histocompatibility complex class I H-2Kq, H-2Dq, and H-2Lq and class II I-Aq markers were undetectable in vitro before or after interferon gamma treatment. Together with H-2K allele typing, which confirmed the Swiss mouse origin of the donor cells, these observations indicate that mouse-derived STO cell lines can differentiate along hepatocytic lineage and engraft into rat liver across major histocompatibility barriers.

Animals↗

PubMed2004

Derivation and study of human epithelial cell lines resistant to killing by chromium trioxide.

CrO3 is cytotoxic for human epithelial 293 kidney cells over a narrow concentration range of approximately 2-8 microM (D50 approximately 3.0 microM); significantly greater toxicity is observed in clonogenic assays (D50 approximately 0.1-1.0 microM). Survival of a small fraction of cells (< or = 0.1%) at CrO3 concentrations between 10(-5) to 10(-3) M, and first-order kinetics of cytotoxicity, rationalized the derivation of a new panel of transformed human epithelial cell lines resistant to cytotoxic concentrations of CrO3 over the range of 5-100 microM. Wild-type and Cr-resistant 293 cell lines display similar morphology under phase microscopy, but wild-type cells grow faster and reach stationary phase sooner than Cr-resistant cells. The Cr-resistant phenotype is stable, and it is specific, since Cr-resistant cells are killed by NiSO4 or by CdCl2 at concentrations equivalent to those that kill wild-type cells. Toxicity analysis curves subjected to target theory suggest that the Cr-resistant cell lines have fewer Cr-sensitive "targets" and have undergone a "loss of function" compared to wild-type cells. This loss of function may be related to significantly lower rates of uptake of Na2(51)CrO4,which correlate inversely with CrO3 concentrations used for the selection and maintenance of the Cr-resistant lines, and to reduced levels of an approximately 96-kDa protein in comparison to wild-type cells. This new panel of Cr-resistant transformed human epithelial kidney cell lines will be useful in comparative studies of genetic resistance and sensitivity to human Cr(VI) toxicity, sulfate transport, and growth control differences between wild-type and Cr-resistant cells.

Apoptosis↗

PubMed2004

Interactive DNA sequence and structure design for DNA nanoapplications.

DNA sequence and structure design is very important for DNA nanoapplications. A computer-aided design tool is needed for exploring DNA sequence and structure of interests before experimental synthesis, which is a time- and labor-consuming process. In this paper, an interactive DNA sequence and structure design software tool called DNA shop is proposed and implemented. The visualization tool can generate DNA structures by specifying, selecting, and moving DNA sequences around and display corresponding structures. Using the tool, DNA sequence and structure can be visually inspected in three-dimensional space before experimental studies.

Algorithms↗

PubMed2004

[Simultaneous determination of neopterin and biopterin in urine by high performance liquid chromatography].

UNLABELLED: A method was established for simultaneous determination of neopterin (NP) and biopterin (BP) in urine by high performance liquid chromatography-fluorescence detection. CONDITIONS: column, Hypersil BDS C18 (4.6 mm i. d. x 200 mm, 5 microm); mobile phase, methanol-water (10:90, v/v); flow rate, 0.5 mL/min; column temperature, 20 degrees C; excitation wavelength, 360 nm; emission wavelength, 440 nm. Urine samples were first precipitated with trichloroacetic acid, then centrifuged at 12 000 r/min for 15 min at 4 degrees C, and finally added with NaOH to neutralize the supernatant. Injection volume was 30 microL. The linear ranges of determination of the standards NP and BP were 0.12 - 1000 microg/L and 0.48 -1000 microg/L, with the detection limits of 0.01 microg/L and 0.1 mictog/L, the relative standard deviations (RSDs) in urine of 1.09% and 3.39%, and average recoveries of 100.7% and 100.3%, respectively. The concentrations of NP and BP, and concentration ratio of NP and BP in urines were detected and compared between controls and uremia patients. The concentration of creatinine (Cr) in urines was detected with picric acid method. The concentration ratios of NP and Cr, NP and BP in uremia group increased more significantly than that in normal group (P < 0.05). The method is simple, fast, accurate and convenient. It can be used to detect NP and BP for clinical urine samples and provide a more convenient and accurate tool for the diagnosis of patients.

Biopterins↗

PubMed2003

Hepatic progenitor cell lines from allyl alcohol-treated adult rats are derived from gamma-irradiated mouse STO cells.

In attempts to recharacterize several markers of putative rat liver progenitor cells, single-stage reverse transcription-polymerase chain reaction (RT-PCR) analyses failed to confirm the reported immunochemical detection of albumin, alpha(1)-fetoprotein, and cytochrome P450-1A2 in the clonal line, 3(8)#21, and the cloned derivative, 3(8)#21-EGFP (enhanced green fluorescent protein). Undetectable expression occurred whether or not both lines were cultured on or off feeder layers of gamma-irradiated mouse embryonic STO (SIM [Sandoz inbred Swiss mouse] thioguanine-resistant ouabain-resistant) cells. PCR amplification of liver progenitor cell chromosomal (rat and mouse Pigr, rat INS1, mouse INS2) and mitochondrial (rat and mouse COX1) genes revealed only mouse sequences. Further analyses of rat and mouse COX1 sequences in cells from untampered storage vials of all 11 reported liver progenitor cell lines and strains revealed only mouse sequences. In addition, uniquely similar metaphase spreads were observed in STO, 3(8)#21, and 3(8)#21-EGFP cells. The combined results suggest that the previously reported "rat" liver progenitor cell lines were most likely generated during early derivation in cell culture from gamma-radiation-resistant or ineffectively irradiated mouse STO cells used as the feeder layers. These findings reveal new types of artifacts encountered in cocultures of tissue progenitor cells and feeder layer cell lines, and they sound a cautionary note: phenotypic and genotypic properties of feeder layers should be well-characterized before and during coculture with newly derived stem cells and clonal derivatives.

Animals↗

PubMed2002

[Whether the impairment of grafted liver was induced by the inflammatory cells in cold and warm ischemia after transplantation].

OBJECTIVE: To investigate whether the impairment of grafted liver after transplantation was induced by the same inflammatory cells in cold and warm ischemia. METHODS: Male SD rats were divided into two groups randomly, 24 grafted livers in each group were stored for 120 or 240 min at 4 degrees Centigrade Ringer's solution. Also male SD rats were divided into three groups, in which 24 grafted livers in each group were experienced warm ischemia ranged from 90, 120 to 150 min from non-heart-beating donor. The recipients were killed after 1, 3, 6, and 24 hours of transplantation for sample collection. RESULTS: Along with the prolongation of cold and warm ischemia time, the serum ALT and AST levels were increased gradually after transplantation. Light microscopy showed some necroses in hepatocytes after 3 and 6 hours of transplantation in cold ischemia, and some neutrophilic infiltration in sinusoids. There were a large number of hepatocytes necroses after 3, 6 hours of transplantation in warm ischemia from non-heart-beating donor and a lot of lymphocytic infiltration in sinusoids. The findings in electron microscopy were as the same as those found in light microscopy, and the lymphocytes which infiltrated in sinusoids in warm ischemia were identified as T lymphocytes in electron microscopy. CONCLUSIONS: The impairment of grafted livers after transplantation seems to be induced by two different inflammatory cells in cold and warm ischemia, that is, neutrophils mediate the cold ischemia-reperfusion, and T lymphocytes mediate the warm ischemia-reperfusion from non-heart-beating donor.

Alanine Transaminase↗

PubMedDate not supplied

Bio-microarray fabrication techniques--a review.

Microarrays with biomolecules (e.g., DNA and proteins), cells, and tissues immobilized on solid substrates are important tools for biological research, including genomics, proteomics, and cell analysis. In this paper, the current state of microarray fabrication is reviewed. According to spot formation techniques, methods are categorized as "contact printing" and "non-contact printing." Contact printing is a widely used technology, comprising methods such as contact pin printing and microstamping. These methods have many advantages, including reproducibility of printed spots and facile maintenance, as well as drawbacks, including low-throughput fabrication of arrays. Non-contact printing techniques are newer and more varied, comprising photochemistry-based methods, laser writing, electrospray deposition, and inkjet technologies. These technologies emerged from other applications and have the potential to increase microarray fabrication throughput; however, there are several challenges in applying them to microarray fabrication, including interference from satellite drops and biomolecule denaturization.

Biotechnology↗